Arteriovenous Fistula Research Articles

Comparison of nBCA and Onyx for Embolization of Spinal Dural Arteriovenous Fistulas

Background Endovascular embolization can effectively treat spinal dural arteriovenous fistulas (SDAVFs). One factor limiting the success and durability of endovascular treatments is reliably casting and occluding the draining vein. We sought to compare the efficacies of n ‐butyl‐2‐cyanoacrylate (nBCA) and Onyx in the treatment of SDAVFs. Methods We retrospectively analyzed patients with SDAVFs treated with endovascular embolization for whether a “durable cure” was achieved, defined as complete obliteration, clinical improvement, and sustained radiologic cure on follow‐up. We compared the outcomes of patients treated with Onyx to those treated with nBCA. Results A total of 40 embolizations for SDAVFs were performed in 38 patients. All patients were treated exclusively with liquid embolysates: Onyx alone (n = 22), nBCA alone (n = 16), or nBCA and Onyx combined (n = 2). For 45% (10/22) of patients treated with Onyx only, complete obliteration of the fistula with casting of the vein was not achieved. These patients were referred for microsurgical ligation. For all 16 patients treated with nBCA only, complete obliteration of the fistula was achieved. All 16 patients exhibited a durable cure compared with 11 of 22 patients (50%) in the Onyx‐only group ( P = 0.002). Conclusion nBCA may be superior to Onyx for the embolization of SDAVFs. nBCA embolization is safe and effective for a subset of SDAVFs. Prospective studies comparing SDAVF treatment strategies are warranted.

High-intensity Focused Ultrasound Ablation Combined with Hysteroscopy for the Treatment of Uterine Arteriovenous Fistula Associated with Retained Products of Conception: A Prospective Cohort Study

To evaluate the efficacy of combining high-intensity focused ultrasound (HIFU) ablation with hysteroscopic removal of retained products of conception in the presence of a uterine arteriovenous fistula (UAVF). Prospective cohort study SETTING: Tertiary hospital. 17 patients with UAVF and retained products of conception. HIFU ablation combined with hysteroscopic removal of retained products of conception RESULTS: All patients presented with irregular vaginal bleeding following pregnancy termination and not responsive to medical treatment. Patients were confirmed to have a UAVF along with concurrent intrauterine residue using three-dimensional color Doppler ultrasonography, uterine angiography, or pelvic-enhanced magnetic resonance imaging; and demonstrated a poor response to medical treatment. Under real-time ultrasound guidance, HIFU was used to ablate the arteriovenous malformation region. Patients underwent hysteroscopic removal of retained products of conception; the removed tissue was subjected to pathological examination. All patients underwent monthly uterine color Doppler ultrasound examinations and menstrual status follow-up within 3 months postoperatively and showed normal menstrual recovery without signs of arteriovenous malformations on ultrasonography. Pathological examination of the tissues removed during hysteroscopic clearance revealed characteristics consistent with pregnancy, with abnormal blood vessels in some tissues. All patients experienced normal menstrual recovery postoperatively, without intrauterine adhesions. Combining HIFU ablation with postoperative hysteroscopic surgery effectively treats pregnancy related UAVF with minimal complications, preserves fertility; it offers an additional treatment option for patients wanting future fertility.

Commentary: The effect of virtual reality distraction on haemodialysis patients' pain and anxiety during arteriovenous fistula puncture: a randomised controlled trial.

Commentary: The effect of virtual reality distraction on haemodialysis patients' pain and anxiety during arteriovenous fistula puncture: a randomised controlled trial.

Stereotactic radiosurgery for anterior cranial fossa dural arteriovenous fistulas.

Anterior cranial fossa (ACF) dural arteriovenous fistulas (DAVFs) are notoriously malignant vascular abnormalities, and their drainage into the cortical vein poses a high risk of intracranial hemorrhage (ICH). Stereotactic radiosurgery (SRS) is increasingly seen as an alternative to microsurgery or embolization for the treatment of DAVFs; however, researchers have yet to report on its applicability to ACF DAVFs. This paper summarizes the authors' experience in the use of SRS for ACF DAVFs. The authors' objective was to gain a preliminary overview of SRS outcomes in the treatment of ACF DAVFs. This retrospective study examined all patients who underwent SRS for ACF DAVFs at a single academic medical center between November 2000 and November 2023. Demographic data, DAVF characteristics, and clinical outcomes were obtained from medical records. A total of 12 patients diagnosed with ACF DAVFs were treated using SRS. One patient was lost to follow-up. The mean age was 54.8 years and men comprised 82% of the cohort. The most common presenting symptoms included headache (n = 5), ocular symptoms (n = 3), seizure (n = 2), anosmia (n = 1), and tinnitus (n = 1). Two patients were asymptomatic. Four patients (36%) initially presented with ICH. Nine patients exhibited DAVF Cognard type IV, and 2 patients exhibited Cognard type III. DAVF obliteration in 7 of the 11 patients (64%) was confirmed by brain MR angiography (n = 4) or digital subtraction angiography (n = 3). No post-SRS episodes of ICH were reported. Most of the patients (10 of 11) reported improvements in clinical symptoms. SRS appears to be a viable alternative treatment for ACF DAVFs, particularly for patients who are not suitable candidates for surgery or those with an unfavorable angioarchitecture.

Life-threatening gross hematuria caused by giant renal artery branch aneurysm coexistent with artero-venous fistula leading to acute rupture of renal pelvis

Life-threatening gross hematuria caused by giant renal artery branch aneurysm coexistent with artero-venous fistula leading to acute rupture of renal pelvis

Validation of arteriovenous access stage (AVAS) classification: a prospective, international multicentre study.

The arteriovenous access stage (AVAS) classification provides evaluation of upper extremity vessels for vascular access (VA) suitability. It divides patients into classes within three main groups: suitable for native fistula (AVAS1) or prosthetic graft (AVAS2), and patients not suitable for conventional native or prosthetic VA (AVAS3). We validated this system on a prospective dataset. A prospective, international observational study (NCT04796558) involved 11 centres from 8 countries. Patient recruitment was from March 2021 to January 2024. Demographic data, risk factors, vessels parameters, VA types, AVAS class and early VA failure were collected. Percentage agreement was used to assess predictive ability of AVAS (comparison of AVAS and created VA) and consistency of AVAS assessment between evaluators. Pearson's Chi-squared test was used for comparison of early failure rate of conventional (predicted by AVAS) and unconventional (not predicted by AVAS) VA. From 1034 enrolled patients, 935 had arteriovenous fistula or graft, 99 patients did not undergo VA creation due opting for alternative renal replacement therapies, experiencing health complications, death or non-compliance. AVAS1 had 91.2%, AVAS2 7.2% and AVAS3 1.6% of patients. Agreement between evaluators was 89%. The most frequently created VAs were radial-cephalic (46%) and brachial-cephalic (27%) fistulae. The accuracy of AVAS versus created access was 79%. In comparison, VA predicted by clinicians versus created access was 62.1%. Inaccuracy of AVAS prediction was more common with higher AVAS classes, and the most common reason for inaccuracy was creation of distal VA despite less favourable anatomy (17%). Patients with unconventional VA had higher early failure rate than patients with conventional VA (20% vs 9.3%, respectively, P=.002). AVAS is effective in predicting VA creation, but overall accuracy is reduced at higher AVAS classes when the complexity of decision-making increases and proximal vessels require preservation. When AVAS was followed by clinicians, early failure was significantly decreased.

Resection of uterine arteriovenous fistula with temporary occlusion of the internal iliac arteries: Case series and literature review.

Uterine arteriovenous fistula (UAVF) is a rare vascular abnormality that can cause severe and potentially life-threatening hemorrhage. Uterine artery embolization is a common treatment that may affect ovarian and uterine perfusion and cause fertility problems. We herein report our experience treating 2 patients with UAVF who underwent resection after temporary occlusion of both internal iliac arteries. Both patients presented with a large UAVF after incomplete miscarriages in the second trimester. Magnetic resonance imaging revealed a UAVF measuring 3.6 × 2.6 × 2.1 cm over the myometrium of the posterior uterine in case 1, and a UAVF of 7.1 × 4.1 × 4.5 cm was identified in case 2. Uterine arteriovenous fistula, retained products of conception. The patients underwent resection of UAVF with temporary occlusion of the internal iliac arteries and hysteroscopic removal of the retained products of conception. Intraoperative bleeding were minimal. Neither patient exhibited abnormal uterine bleeding at the 6-month follow-up. Follow-up ultrasonography and magnetic resonance imaging showed normal uterine myometrium and endometrium and no residual disease. UAVF resection after temporary occlusion of the internal iliac arteries is a promising treatment approach for UAVF. This technique can reduce intraoperative bleeding and remove the potential hemorrhage-related lesion while preserving fertility.

Scalp Arteriovenous Malformation. Percutaneous Multistage Ligature under Ultrasound Guidance: Palliative Technique to be Considered. Case report.

Background: Scalp arteriovenous malformations (AVMs) are fast-flow malformations characterized by the presence of arteriovenous shunting without an intervening capillary bed within the subcutaneous layer. Aim: To report a case of AVMs managed by percutaneous multistage ligature under ultrasound guidance. Case report: A 68-year-old patient with a AVMs was managed by percutaneous multistage ligature under ultrasound guidance with acceptable cosmetic and functional results. Conclusion: Some patients with bad health conditions and a high risk of anesthesia with comorbidities can benefit from multistage transcutaneous ligation of the principal arterial pedicular under ultrasound guidance. This simple and palliative technique must be considered in some cases.

Microsurgical treatment for superior petrosal sinus dural arteriovenous fistulas.

Superior petrosal sinus (SPS) dural arteriovenous fistulas (DAVFs) are a commonly encountered type of tentorial DAVF that occasionally requires microsurgical intervention. This study aims to analyze the tributaries of the superior petrosal vein (SPV) observed intraoperatively, their association with clinical symptoms, and venous drainage patterns.This retrospective study reviewed 34 consecutive patients with SPS DAVFs who underwent microsurgical treatment at a single institution between 2014 and 2022.The cohort had a mean age of 52.8 ± 11.8 years, with 85.3% (29/34) being male. Predominant symptoms included venous hypertensive myelopathy (VHM) (55.9%) and intraparenchymal or subarachnoid hemorrhage (23.5%). Standard retrosigmoid approach was used to ligate 94.1% (32/34) of the lesions, resulting in immediate complete fistula occlusion for all patients. Supratentorial venous drainage patterns were associated with a higher incidence of intracranial hemorrhage and venous varix (P = 0.047). Infratentorial drainage patterns were more frequently linked with VHM-related symptoms (P<0.001). Patients presenting VHM-related symptoms showed a higher prevalence of drainage through the vein of the cerebellopontine fissure (VCPF) (P = 0.01), while those with intracranial hemorrhage symptoms exhibited a higher prevalence of pontotrigeminal vein (PTV) drainage (P = 0.033) in their DAVFs.Endovascular management of SPS DAVFs carries inherent risks. Surgical treatment via standard retrosigmoid craniotomy offers favorable clinical outcomes with high rates of cure. In cases featuring infratentorial venous drainage, the predominant arterialized tributary of the SPV was the VCPF, commonly associated with VHM-related symptoms. Conversely, in cases with supratentorial venous drainage, the predominant arterialized SPV tributary was the PTV, often associated with intracranial hemorrhage symptoms.

Hand Digit Revascularization: Could Be an "Elective-Urgence" Surgery?

Background: A continuous obstacle that has limited access to and implementation of finger replantation surgery is timeliness, as ischemia time is traditionally considered a crucial factor for success. However, claims that the vitality of amputated fingers decreases after 6 h of warm ischemia and 12 h of cold ischemia are mostly based on theoretical considerations. Methods: Here we present a case of multi-digit revascularization after 72 h of warm ischemia using the microsurgical arteriovenous bypass technique. Results: In the reported case, revascularization was performed after a long ischemic period and showed good recovery of motor and sensory function. Conclusions: We identified significant limitations in the literature supporting time limits of ischemia and recent evidence demonstrating the feasibility of delayed finger replantation. The current treatment approach for amputation injuries often requires transfers or nighttime emergency procedures, increasing costs and limiting the national availability of finger replantation. Changes to finger replantation protocols based on evidence could expand access to this service and improve the quality of care.

Effects of far infrared therapy in hemodialysis arterio-venous fistula maturation: A meta-analysis.

Hemodialysis patients rely on stable vascular access to perform effective hemodialysis and reach good dialysis quality. However, an obstructed or under-matured arteriovenous fistula (AVF) may increase infection rate and mortality in hemodialysis patients. Far infrared (FIR) therapy might help to promote AVF maturation and reduce obstruction rate. Therefore, this meta-analysis was conducted to evaluate the effect of FIR therapy on AVF obstruction rate and maturation. PubMed, Embase, the Cochrane Library, and other databases which provide publications in randomized controlled trials (RCTs) of FIR to improve AVF in patients with CKD (Chronic Kidney Disease) or HD (hemodialysis) were used to collect articles which published before February 2023. Two authors selected relevant articles independently based on pre-defined inclusion and exclusion criteria, and assessed the quality of the articles by using the Cochrane Handbook before performing a meta-analysis in Review Manager (RevMan) 5.4 software. Four RCTs with 475 patients were included. The results of the meta-analysis showed that the FIR therapy groups had better physiological maturation at 3 months (RR = 1.22; 95% CI = 1.07 to 1.39; p = .002) and clinical maturation at 12 months (RR = 1.35; 95% CI = 1.14 to 1.60; p < .001) than the control groups without FIR therapy. The obstruction rates within 12 months were much lower in the FIR therapy groups than in the control groups (RR = 0.24; 95% CI = 0.08 to 0.68; p = .007), also, there was no statistical heterogeneity. FIR could promote fistula maturation and reduce the incidence of AVF obstruction.

Sonographic Appearance of Hemodialysis Reliable Outflow Graft (HeRO Graft)

HeRO Graft (Hemodialysis Reliable Outflow Graft) consists of 3 components; an arterial graft component, a titanium connector and a venous outflow component. It is implanted under the skin of end-stage renal failure patients as a subcutaneous permanent access. It is a vascular graft that traverses central venous stenosis and has no venous anastomosis, thus providing blood flow from an artery direct into the central venous system. Ultrasound imaging of the 3 components of the HeRO graft is performed and described in this article. Equipment used include Phillips ultrasound machines CX-50, iU22, and EPIQ 7 with linear transducers of frequency 3 to 15 MHz and curvilinear transducers of frequency 1 to 5 MHz. HeRO graft is often the last hemodialysis access available for patients on long-term dialysis who would have typically exhausted all other hemodialysis options like the native arterio-venous fistula (AVF) and arterio-venous graft (AVG). As long-term dialysis patients run out of typical AVF/AVG accesses coupled with the increasing longevity of persons in countries where advanced medical technology is available, subcutaneously implanted grafts such as the HeRO graft may become more commonplace. Description of the sonographic appearance of the various components of the HeRO graft may help sonographers who are not familiar with the graft to image the components.

Spinal arteriovenous fistula leading to acute paraplegia after a lumbar nerve root block: Successful embolization with complete neurological recovery-a case report.

Spinal arteriovenous fistulas (SAVFs) are the most common type of vascular malformation of the spine in adult patients. They can lead to acute or progressive myelopathy due to venous congestion of the medullary veins. While most SAVFs are acquired, their pathophysiology remains unclear. The natural history of the disease and its clinical presentation are highly influenced by the location of the fistula and various factors may trigger sudden neurological decline. We present a case of a patient who developed a complete spinal cord injury after a lumbar nerve root block, likely due to an undiagnosed SAVF. The patient underwent endovascular embolization, resulting in a complete recovery of neurological function.

Endovascular management of pediatric pial arteriovenous fistulas with hereditary GDF2 mutation: illustrative case.

Intracranial pial arteriovenous fistulas (PAVFs) are uncommon neurovascular anomalies that primarily affect the pediatric population. PAVFs are often linked to hereditary hemorrhagic telangiectasia, yet the specific genetic mutations remain unidentified. While endovascular embolization is the preferred treatment for PAVFs, complications like hydrocephalus and sinus thrombosis pose challenges in management. The authors present a rare case of PAVF in a 6-month-old male neonate with a hereditary GDF2 mutation, where the fistula was supplied by the posterior inferior cerebellar artery and drained directly into the sigmoid sinus. The PAVF was effectively treated with endovascular embolization using coils and Onyx. Furthermore, the authors describe the successful use of rivaroxaban in managing subsequent sinus thrombosis after the embolization of PAVFs. Additionally, the authors review treatment strategies and complications following fistula disconnection. Endovascular embolization is the primary treatment choice for the majority of pediatric PAVFs, while a hereditary GDF2 mutation is considered a potential contributing factor to the formation of these malformations in children. Rivaroxaban has shown promise as an effective therapeutic option for pediatric sinus thrombosis, supported by its established safety profile. https://thejns.org/doi/10.3171/CASE24182.

Pediatric interventional neuroradiology: "How I do it" vol. II-Embolization.

Pediatric arteriovenous shunts can be challenging to embolize and the consequences of excess venous penetration disastrous. Moreover, the congenital nature of most shunts necessitates neonatal intervention whenever (medically refractory) heart failure occurs. Here, we describe current endovascular treatment strategies based on personal experience and literature review. While disparate, arteriovenous malformation, dural arteriovenous fistula (AVF), pial AVF, and vein of Galen aneurysmal malformation share unifying features such as high output heart failure and venous hypertension. This tutorial is divided into passages on Goals, Access, and Treatment which respect differences among pediatric arteriovenous shunts while maintaining a narrative economy.

Low Serum Albumin Levels are Associated with Short-Term Recurrence of Arteriovenous Fistula Failure.

Vascular access intervention therapy (VAIVT) is widely used as a treatment for arteriovenous fistula (AVF) failure. However, recurrent AVF failure is a major concern for dialysis patients. By prospectively observing patients after an initial VAIVT, we attempted to identify risk factors for developing restenosis of AVF. This single-center prospective study evaluated 57 patients who underwent their first VAIVT procedure at our hospital from April 2022 through March 2023. We performed blood and biochemical tests during the first VAIVT to collect data on clinical variables. Ultrasonography was used to measure vessel diameter reduction rate, flow volume (FV) reduction rate, and increase in resistance index (RI) rate over a 3-month period. Within 3 months, 24 patients developed short-term shunt stenosis and 30 did not. Three were not traceable. In a comparison of the two groups, significant differences were observed in albumin (ALB), FV, RI, and elbow shunt. Analysis of change rates in the three ultrasound findings identified five factors (hematocrit, platelet count, activated partial thromboplastin time, ALB, and FV). The results of logistic regression models revealed that ALB was the most significant predictive factor for short-term shunt stenosis (p = 0.031). In conclusion, our findings suggest that low serum ALB at the time of initial VAIVT is a significant risk factor for short-term recurrence of AVF failure in hemodialysis patients. These findings emphasize the importance of careful routine monitoring to reduce the risk of AVF failure and associated complications.

Utility of covered stents as a bypass for the treatment of central venous occlusion: a case report

BackgroundCentral venous occlusion (CVO) is difficult to treat with percutaneous transluminal angioplasty because the guidewire cannot pass through the occluded segments. In this study, we devised a new method for establishing an extra-anatomic bypass between the right subclavian vein and the superior vena cava via a covered stent to treat whole-segment occlusion of the right brachiocephalic vein (BCV) with calcification.Case presentationWe present the case of a 58-year-old female patient who complained of right arm swelling present for 1.5 years. Twelve years prior, the patient began hemodialysis because chronic glomerulonephritis had progressed to end-stage renal disease. During the first 3 years, a right internal jugular vein (IJV)-tunneled cuffed catheter was used as the dialysis access, and the catheter was replaced once. A left arteriovenous fistula (AVF) was subsequently established. Owing to occlusion of the left AVF, a new fistula was established on the right upper extremity 1.5 years prior to this visit. Angiography of the right upper extremity revealed complete occlusion of the right BCV and IJV with calcification. Because of the failure to pass the guidewire across the lesion, we established an extra-anatomic bypass between the right subclavian vein and the superior vena cava with a covered stent. Angiography confirmed the patency of whole vascular access system. After 3 months of follow-up, the patient’s AVF function and the bypass patency were satisfactory.ConclusionsAs a new alternative for the treatment of long, angled CVO with or without calcification, a covered stent can be used to establish an extravascular bypass between central veins.

Mechanical thrombectomy with the InThrill device for thrombosed hemodialysis access: A single center experience.

To assess the effectiveness and safety of the InThrill Thrombectomy System in treating thrombosed arteriovenous fistulas (AVFs) and grafts (AVGs) via mechanical thrombectomy. Institutional database was retrospectively searched to identify all thrombectomy procedures performed using the study device at our hospital for thrombosis of AVFs or AVGs. Inclusion criteria encompassed patients aged 18 and above who underwent AV access thrombectomy using the study device. Intraprocedural metrics, including procedure time, device time, blood loss, and adjunctive procedures were collected. Technical success was defined as restoration of flow combined with <30% residual diameter stenosis of the treated vascular segment. Clinical success was defined as the resumption of normal hemodialysis for a minimum of at least one session following intervention. Through 3-month follow-up, patency, and adverse events were evaluated. A total of 20 thrombectomies were performed on 2 AVFs and 18 AVGs in 13 patients. Median procedure and device times were 45 and 10 min, respectively. Balloon angioplasty was performed in all cases with additional stenting in 40% (8/20) of cases to address stenosis following thrombus removal. No other mechanical thrombectomy devices were utilized. Intraprocedural thrombolytics were not administered in any case. Average blood loss was 10 mL. The technical success and clinical success rates were 100% (20/20) and 95% (19/20), respectively. There were no intraoperative adverse events. One patient developed a post-operative minor hematoma, and one patient developed a post-operative pseudoaneurysm at the access site. The primary patency rate was 77% (10/13) at 1 month. Both assisted primary and secondary patency rates were 100% at 1 and 3 months. These preliminary results suggest that the InThrill Thrombectomy System is rapid, safe, and effective for thrombolytic-free treatment of AV access thrombosis in hemodialysis patients.

CT guided sharp recanalization to restore dialysis access in patients with central venous obstruction: A single centre experience and review of alternative techniques.

Central venous obstructions that impedes catheter placement or results in catheter dysfunction is a significant problem for haemodialysis patients. Recanalization can be performed with an intent to restore central venous access, improve outflow from arteriovenous fistula or to relieve symptomatic venous obstructions. Sharp recanalization encompasses various interventional techniques using a sharp instrument to puncture through or bypass around a venous obstruction. In this paper we outline our experience performing CT guided sharp recanalization and review alternative sharp recanalization techniques that are specifically used to restore haemodialysis access in patients with thoracic central venous obstruction.

Anatomical Feasibility of Percutaneous Arteriovenous Fistula Formation in Korea.

Currently, there are two types of percutaneous arteriovenous fistula (pAVF) formation systems approved by the FDA: Ellipsys and WavelinQ. Although these systems are already in use in Europe or the United States, they have not been approved for use in Korea yet. For this reason, this study aimed to check anatomical feasibility of these systems for Korean population prior to their actual use. Consecutive patients who received ultrasound vein mapping for arteriovenous fistula formation from June 2021 to June 2022 were included. The anatomical feasibility of each system was confirmed according to the manufacturer's instructions for use (IFU). Upper extremity ultrasonography was performed for a total of 83 patients to determine their feasibility for pAVF formation. Of these patients, 65.1% were feasible for pAVF formation with appropriate deep communicating vein (DCV) and outflow. Among them, 57.8% were feasible for the Ellipsys system and 54.2% were feasible for the WavelinQ system. Most patients who were infeasible for pAVF formation had a DCV of small size. Ulnar vessels were more suitable than radial vessel for WavelinQ (54.2% vs 33.7%, P-value = .012). The most common reason for not meeting the criteria was a small vein size at the access site. More than half of all patients were feasible for pAVF formation in this study. Ellipsys had a higher feasibility than WavelinQ, although they showed no significant difference in the feasibility. If these devices are imported into Korea, it will be a good opportunity for many patients to reduce the surgical burden and create AVFs more easily through these procedures.